st7fmc2s7t6 STMicroelectronics, st7fmc2s7t6 Datasheet - Page 188

• Manufacturer Part Number: st7fmc2s7t6
• Description: 8-bit Mcu With Nested Interrupts, Flash, 10-bit Adc, Brushless Motor Control, Five Timers, Spi, Linsci
• Manufacturer: STMicroelectronics

ST7MC1/ST7MC2
MOTOR CONTROLLER (Cont’d)
This sets the minimum off time of the PWM signal
generated by this internal clock. This off time can
vary depending on the output of the current feed-
back comparator. In sensor mode (SR=1) and
when the sampling for the Z event is done during
the PWM ON time in sensorless mode (SPLG bit is
set in MCRC register and /or DS[3:0] bits with a
value other than 000 in MCONF register), there is
no minimum OFF time required anymore, the min-
imum off time is set automatically to 0µs and the
OFF time of the PWM signal is controlled only by
the current regulation loop.
Table 47. Sampling Frequency Selection
Note: Times are indicated for 4 MHz f
Figure 107. Sampling clock generation block
188/308
1
f
SA3 SA2 SA1 SA0
PERIPH
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
MPWME Register
MPRSR Register
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
Frequency logic
Off-Time logic
SA[3:0] bits
OT[3:0] bits
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
4
2
Sampling Frequency
33.33 KHz
50.0 KHz
40.0 KHz
25.0 KHz
20.0 KHz
18.1 KHz
15.4 KHz
12.5 KHz
6.25 KHz
3.13 KHz
1.56 KHz
1.25 KHz
10 KHz
961 Hz
625 Hz
390 Hz
It can be configured to 8MHz with the XT16: XT8 bits in the MCONF register
Note: The MTC controller input frequency (
.
PERIPH
Sampling
Clock
0
Warning: If the off time value set is superior than
the period of the PWM signal (for example 40µs off
time for a 50KHz (25µs period) PWM frequency),
then the signal output on MCOx pins selected is a
100% duty cycle signal (always at 1).
Table 48. Off time table
Note: Times are indicated for 4 MHz f
OT3 OT2 OT1 OT0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
The BEMF is sampled at the end of OFF time
in sensorless mode
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
T
T
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
f
off
sampling
PERIPH
sorless mode
(measurement window)
Off Time sen-
(DS[3:0]=0)
Frequency
OFF time
32.5
37.5
12.5 µs
17.5 µs
22.5 µs
27.5 µs
(SR=0)
2.5 µs
7.5 µs
35
40
)
10 µs
15 µs
20 µs
25 µs
30 µs
5 µs
is 4 MHz in this example,
s
s
s
s
pling during ON
(SR=1) or sam-
time in sensor-
No minimum off
and/or DS[3:0]
less (SPLG =1
Sensor Mode
PERIPH
bits)
time